Starvation hibernation stops the biological clock
Over the past 80 years, scientists have conducted many experiments in which the ability of a low-calorie diet has been demonstrated to increase the life expectancy of various model organisms, including rats, mice, yeast, fruit flies, spiders, fish, monkeys and nematodes by 30%-200%.
Duke University researchers working under the guidance of Associate Professor David R. Sherwood have demonstrated that food deprivation suspends the development of C.elegans roundworms. Nematodes continue to move in search of food, but their cells and organs stop aging and go into a state of rest. When food appears, the development of worms resumes and continues in a normal mode, but as a result, their life expectancy can be doubled.
In natural conditions, organisms such as C.elegans invariably encounter periods of nutrient deficiency that affect their development. In earlier experiments, the authors demonstrated that placing the eggs of these nematodes in a nutrient-depleted environment completely stops their development.
The object of their recent research was the last two stages of the development of C.elegans larvae – L3 and L4 – on which the formation of important tissues and organs, such as the vulva, takes place. At these stages, the vulva of nematodes develops from a lump consisting of 3 cells into a structure of 22 cells. Experiments have shown that deprivation of food at different stages of development during these two stages stopped the formation of the vulva only at the stages when it consisted of 3 or 22 cells. Further experiments showed that in conditions of hunger, the development of all tissues and cells of the body stopped at one of two critical stages.
Nematode C.elegans, whose muscle cells are marked with green, and germ cells with red fluorescent dye. The development of these and other cells freezes at one of the two critical stages of development, which suspends the aging of nematodes for the period of hunger.The authors also showed that the normal development of nematodes resumes even after prolonged fasting for at least two weeks.
By suspending the biological clock, this prolongs the life of worms twice.
The researchers believe that the observations made extend to malignant cells. Until now, no one could explain why tumor cells that metastasized in the early stages of the disease can remain dormant for many years, after which they lead to a relapse of the disease. It is quite possible that they use mechanisms similar to those that help nematode cells survive unfavorable periods for life.
Currently, the authors are searching for genetic mechanisms that can reversibly stop the development of C.Elegans.
Article by Adam J. Schindler et al. Identification of Late Larval Stage Developmental Checkpoints in Caenorhabditis elegans Regulated by Insulin/IGF and Steroid Hormone Signaling Pathways is published in the journal PLoS Genetics.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Duke University:
Strict Diet Suspends Development, Doubles Lifespan of Worms.
24.06.2014